ENSO stands for which of the following?

• A. El Niño-Southern Oscillation
• B. El Niño and the Southern Oscillation
• C. El Niño Oscillation Southern
• D. Southern Oscillation Only

Answer: (A)

ENSO is a single climate pattern in the tropical Pacific that arises from interactions between the ocean and atmosphere, producing variations in sea surface temperature and atmospheric circulation. The name combines the two biggest aspects: El Niño (the ocean warming in the central/eastern Pacific) and the Southern Oscillation (the atmospheric pressure changes that drive trade winds and rainfall patterns). Therefore the standard term is El Niño-Southern Oscillation, with the hyphen reflecting their connection as one coupled phenomenon. The choice that spells it exactly that way is the best fit. Saying “El Niño and the Southern Oscillation” is close but not the conventional form, and “Southern Oscillation Only” ignores the oceanic warming that drives the events, while the remaining option is jumbled.